(PS)- If the speed limit along a 20-mile section of rail track is reduced from 40 miles per hour to 30 miles per hour.

[Max@Math Revolution]

(PS)- If the speed limit along a 20-mile section of rail track is reduced from 40 miles per hour to 30 miles per hour. Approximately how many minutes more will it take a rail to travel along this section with the new speed limit than it would have taken at the old speed limit?

A) 3
B) 5
C) 8
D) 10
E) 12

[Max@Math Revolution]

Solution: Always apply the IVY approach to solve PS questions accurately thus saving time.

Speed * Time = Distance

Length of the section = 20 miles

Original speed limit: 40 miles per hour

Thus, time is taken to cover this distance = \(\frac{20}{40}\ =\ \frac{1}{2}\)

New speed limit: 30 miles per hour

Thus, time is taken to cover this distance = \(\frac{20}{30}\ =\ \frac{2}{3}\)

Thus, the required difference between the time durations is given = \(\frac{2}{3}\ -\ \frac{1}{2}\) = \(\frac{1}{6}\) hours

=> \(\frac{1}{6}\) * 60 = 10minutes

D is the correct answer.

Answer D.